Grabbing 4 Bins from the step in Auto

[apples000]

We're doing a container grabber this year, and it's actually not that difficult. It's just some PVC pipe, and to keep the thing from wobbling all over the place, we've ran some steel cables from the end of the PVC to various points on the robot. We've over tightened the cables so that the PVC bends a few degrees near the end, resulting in more stiffness.

At the end of auto, surgical tubing will retract it all back into the robot.

It's simple and light enough that I predict teams will be adding these arms onto their robot for the championship.

[who716]

well we are planning once the mechanism is done to grab two at a time, in auto swing them backwards into the auto zone then move to the left and grab the other two and swing them as-well into the auto hopefully within the 15 seconds the way we calculated it is possible with our setup. one small problem we are hoping we can manage with is have two containers 54" off the frame in the same direction while moving could causing tipping. but we can fold them up to center the weight for long distance travel, but by doing that it pretty much eliminates our 15 seconds

[MrJohnston]

Originally Posted by who716

well we are planning once the mechanism is done to grab two at a time, in auto swing them backwards into the auto zone then move to the left and grab the other two and swing them as-well into the auto hopefully within the 15 seconds the way we calculated it is possible with our setup. one small problem we are hoping we can manage with is have two containers 54" off the frame in the same direction while moving could causing tipping. but we can fold them up to center the weight for long distance travel, but by doing that it pretty much eliminates our 15 seconds

Grabbing recycling containers off the step in auto is not a primary goal of ours. However, we will have some capability there... We almost certainly will be able to grab one and, with a little time, might have a good play for a second. Basically, we'll be able to grab any game piece we want, but, to get to those on the step, we'll need to push landfill totes out of the way. Just how much will we be able to do in auto will be better known once the robot is finished.

As the mentor who leads scouting and tactics, I would be watching robots with long grabbing arms like this very closely. It seems to me that the level of precision necessary to be successful would make the construction of such a robot very, very difficult. Moreover, there would be some considerable risks involved in its usage:
* If something is ever-so-slightly misaligned, I could see those long arms knocking the RC's off the step in the wrong direction.
* Again, with a misalignment, should an arm reach too far and contact another robot, it could lead to a red card. (Ref discretion - a hook reaching too far could be seen as "strategic" or "egregious" if it gives a an advantage or affects the other robot.
* There would certainly be concerns with center-of-gravity. How would the robot react if another robot were to grab the same container at (or just after) your robot and pull? Could your robot fall over?

All that said, such a robot could be the ideal partner for ours... I would be watching such a robot very, very closely through preliminary rounds and wanting to know: Did they do it so well that it is the ultimate partner? or, did they miss a step, causing it to be a high risk to be a veritable disaster?

[pilum40]

interesting for lower resourced teams like ours! Got any pics or plans you'd share with us? Please drop me a PM if you could do so.
Thanks!
Steve Miller
Coach 3355
Purple Vipers

Originally Posted by apples000

We're doing a container grabber this year, and it's actually not that difficult. It's just some PVC pipe, and to keep the thing from wobbling all over the place, we've ran some steel cables from the end of the PVC to various points on the robot. We've over tightened the cables so that the PVC bends a few degrees near the end, resulting in more stiffness.

At the end of auto, surgical tubing will retract it all back into the robot.

It's simple and light enough that I predict teams will be adding these arms onto their robot for the championship.

[Kevin Leonard]

Originally Posted by apples000

We're doing a container grabber this year, and it's actually not that difficult. It's just some PVC pipe, and to keep the thing from wobbling all over the place, we've ran some steel cables from the end of the PVC to various points on the robot. We've over tightened the cables so that the PVC bends a few degrees near the end, resulting in more stiffness.

At the end of auto, surgical tubing will retract it all back into the robot.

It's simple and light enough that I predict teams will be adding these arms onto their robot for the championship.

I hope no one has a device stronger and faster than yours that grabs any of the containers. A giant extended PVC arm sounds pretty brittle to me.

[apples000]

Originally Posted by Kevin Leonard

I hope no one has a device stronger and faster than yours that grabs any of the containers. A giant extended PVC arm sounds pretty brittle to me.

Its like 4.5 inches thick schedule 80 PVC. Our latch mechanism yanks the container back when it engages, and our plan is to get their fastest.

That said, I do share your concern and we will have spares.

[BBray_T1296]

Originally Posted by Kevin Leonard

I hope no one has a device stronger and faster than yours that grabs any of the containers. A giant extended PVC arm sounds pretty brittle to me.

It sounds pretty easy to fix to me. At any rate, once they de-limb you they have to content with your giant shattered pvc poles still clinging to the bins. Seems like an effective strategy to neutralize all of the cans.

[Kevin Leonard]

Originally Posted by BBray_T1296

It sounds pretty easy to fix to me. At any rate, once they de-limb you they have to content with your giant shattered pvc poles still clinging to the bins. Seems like an effective strategy to neutralize all of the cans.

And a great way to get penalised. I genuinely wish you good luck on the endeavor. Make it work. Prove me wrong.

[JamesCH95]

I envision horrific carnage when a 4-RC robot grabs their RCs and a single-RC robot grabs onto one of those RCs, and torques the 4-RC robot into oblivion.

Grabbing multiple RC's does seem like a very attractive proposition, but I think that the right single-RC robot will be able to effectively counter this move either by discouragement or by disrupting the initial grab.

[asid61]

Originally Posted by JamesCH95

I envision horrific carnage when a 4-RC robot grabs their RCs and a single-RC robot grabs onto one of those RCs, and torques the 4-RC robot into oblivion.

Grabbing multiple RC's does seem like a very attractive proposition, but I think that the right single-RC robot will be able to effectively counter this move either by discouragement or by disrupting the initial grab.

Only if they're faster. Dropping PVC arms down is pretty fast and could possibly be comparable to a tape measure setup.
If you have yo unfold, forget it. They'll be gone before you can grab one.
Once the can has moved, a tape measure will have a really hard time getting it.

[JamesCH95]

Originally Posted by asid61

Only if they're faster. Dropping PVC arms down is pretty fast and could possibly be comparable to a tape measure setup.
If you have yo unfold, forget it. They'll be gone before you can grab one.
Once the can has moved, a tape measure will have a really hard time getting it.

Why are you making the assumption that the only viable counter-mechanism is a tape measure? Or a PVC arm?

Have you considered the possibility that a robust, strong, arm could grab a can? One that can deploy in <1s, even with the landfill totes.

[Kevin Leonard]

I'm very curious to see how this all plays out, especially with flimsy mechanisms and non-traction drive systems.

[JamesCH95]

Originally Posted by Kevin Leonard

I'm very curious to see how this all plays out, especially with flimsy mechanisms and non-traction drive systems.

Our arm will be comprised primarily of 1x1x1/16 6061 square tubing and .100 aluminum sheet metal. I am optimistic that it won't be too flimsy...

[JVN]

Originally Posted by JamesCH95

Have you considered the possibility that a robust, strong, arm could grab a can? One that can deploy in <1s, even with the landfill totes.

Originally Posted by JamesCH95

Our arm will be comprised primarily of 1x1x1/16 6061 square tubing and .100 aluminum sheet metal. I am optimistic that it won't be too flimsy...

Who gets to determine if said mechanism is safe?
If said mechanism is safe, what if it was <.5s?
What about <0.25s?
What about<0.1s?

There could be a lot of energy involved in moving a "robust, strong, arm" that quickly.

Of course, if you ever come up against a faster arm, the solution is: more energy. What an interesting dilemma we all face.

[marshall]

Originally Posted by JVN

Who gets to determine if said mechanism is safe?
If said mechanism is safe, what if it was <.5s?
What about <0.25s?
What about<0.1s?

There could be a lot of energy involved in moving a "robust, strong, arm" that quickly.

Of course, if you ever come up against a faster arm, the solution is: more energy. What an interesting dilemma we all face.

Thankfully there is an awesome spreadsheet for determining which motors and gearboxes to use to make the arm move that fast!